This is a hard one! Hopefully, this helps you brainstorm!
Pollutants destroy the ecosystem: A study of brine shrimp
Ocean pollutants kill even the smallest of animals
Destruction of the Brine Shrimp Ecosystem
It would be useful to use your hypothesis or question as a title for your project. For instance, "Pollutant [x] hinders the growth of brine shrimp" or "How does pollutant[x] affect brine shrimp growth?".